print(100)
n = 4
a = 1
for i in range(1,n+1):
   a*=i
print (a)
#方法二：递归
n = 4
def jie_cheng(num):
    if num == 1:
        return 1
    else:
        return num * jie_cheng(num - 1)
print(jie_cheng(n))








